问题现象：从机连接主机时报错

  [ERROR] Slave I/O: error connecting to master 'repl@192.168.0.50:3306' - retry-time: 60  retries: 1, Error_code: 2003

可能的原因有：

a、网络不通（是否打开防火墙）

b、复制用户的密码不对

c、指定的master_port端口不对

d、master上的mysql-bin.xxxxxx被误删

e、主库磁盘空间满了

问题现象：

[root@DBproxy app1]# masterha_check_ssh --conf=/data/masterha/app1/app1.cnf

Can't locate MHA/SSHCheck.pm in @INC (@INC contains: /usr/local/lib64/perl5 /usr/local/share/perl5 /usr/lib64/perl5/vendor_perl /usr/share/perl5/vendor_perl /usr/lib64/perl5 /usr/share/perl5 .) at /usr/bin/masterha_check_ssh line 25.

BEGIN failed--compilation aborted at /usr/bin/masterha_check_ssh line 25.

[root@DBproxy app1]# 

问题定位：应该是环境变量的问题

[root@DBproxy app1]# find / -name SSHCheck.pm

/usr/lib/perl5/vendor_perl/MHA/SSHCheck.pm

将相关路径加入PERL5LIB后，问题解决（根本原因是MHA和OS版本不匹配）。

export PERL5LIB=$PERL5LIB:/usr/lib/perl5/vendor_perl/

问题现象：

[root@DBproxy mysql]# masterha_check_repl --conf=/data/masterha/app1/app1.cnf

........

Fri Jul 15 17:40:59 2016 - [error][/usr/lib/perl5/vendor_perl/MHA/ManagerUtil.pm, ln123]

Can't locate MHA/BinlogManager.pm in @INC (@INC contains: /usr/local/lib64/perl5 /usr/local/share/perl5 /usr/lib64/perl5/vendor_perl /usr/share/perl5/vendor_perl /usr/lib64/perl5 /usr/share/perl5 .) at /usr/bin/apply_diff_relay_logs line 24.

BEGIN failed--compilation aborted at /usr/bin/apply_diff_relay_logs line 24.

Fri Jul 15 17:40:59 2016 - [error][/usr/lib/perl5/vendor_perl/MHA/ManagerUtil.pm, ln150] node version on 192.168.0.60 not found! Is MHA Node package installed ?

 at /usr/lib/perl5/vendor_perl/MHA/MasterMonitor.pm line 374

Fri Jul 15 17:40:59 2016 - [error][/usr/lib/perl5/vendor_perl/MHA/MasterMonitor.pm, ln424] Error happened on checking configurations. Died at /usr/lib/perl5/vendor_perl/MHA/ManagerUtil.pm line 151.

Fri Jul 15 17:40:59 2016 - [error][/usr/lib/perl5/vendor_perl/MHA/MasterMonitor.pm, ln523] Error happened on monitoring servers.

Fri Jul 15 17:40:59 2016 - [info] Got exit code 1 (Not master dead).

MySQL Replication Health is NOT OK!

[root@DBproxy mysql]#

问题定位：设置环境变量export PERL5LIB=$PERL5LIB:/usr/lib/perl5/vendor_perl后问题依然没解决。

最后安装版本为el6的MHA（导致问题的版本为el5，该版本的MHA安装目录为/usr/lib/perl5/vendor_perl下），问题解决。